One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10,14,13)(11,17,18,15)(12,16,21,22)(19,24,20,23)(25,26,30,32)(27,28,33,31)(29,34,37,39)(35,36,40,38)(1,2)(3,6)(4,7)(5,8)(9,11)(10,15)(12,19)(13,17)(14,18)(16,23)(20,21)(22,24)(25,27,30,33)(26,31,32,28)(29,35,37,40)(34,38,39,36)(1,3,5,4)(2,6,8,7)(11,18)(15,17)(19,20)(23,24)(26,32)(27,33)(29,37)(36,38)(1,3,5,4)(2,6,8,7)(9,12,14,21)(10,16,13,22)(11,19,18,20)(15,23,17,24)(25,28,30,31)(26,33,32,27)(29,38,37,36)(34,35,39,40)(9,11)(10,15)(12,20)(13,17)(14,18)(16,24)(19,21)(22,23)(25,26)(27,31)(28,33)(29,34)(30,32)(35,38)(36,40)(37,39) involution — undirected(1,4,5,3)(2,7,8,6)(9,13,14,10)(11,17,18,15)(12,16,21,22)(19,23,20,24)(25,29,30,37)(26,34,32,39)(27,35,33,40)(28,36,31,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.